A study on the pieces on seed for mobile peer-to-peer file sharing applications

Piece selection is one of fundamental operations for mobile P2P file sharing applications, to some extent, it would affect the integrity of file what users obtain. Having investigated the feature of piece selection algorithm of BitTorrent carefully, a new piece selection algorithm based on seed control is presented in this paper. Comparing with the piece selection algorithm of BitTorrent, the proposed one(PSASC) requires seed to control the piece selection in order to avoid its repetition. The-set-covering problem and greedy approximation algorithm are utilized to analyze time complexities of piece selection algorithm of BitTorrent and PSASC, and the simulation is given. Results indicate that the time complexity of PSASC outperforms that of BitTorrent, and shorten the time that all pieces on seed are allocated into mobile P2P network. Finally, based on PSASC, the relation between the n pieces on seed and the mean time T~ that each piece has been downloaded is obtained by M/M/1/m/m queuing model.